A randomized controlled trial of the effect of 2-step orthosis treatment for a mallet finger of tendinous origin.

STUDY DESIGN: A randomized clinical trial, with patients treated either by new 2-step orthosis or by the figure-eight-type orthosis with the distal interphalangeal (DIP) joint extended.

PURPOSE OF THE STUDY: To report on our new orthosis and to evaluate the treatment efficacy of using a 2-step orthosis for the treatment of a mallet finger of tendinous origin compared with a conventional orthosis.

METHODS: Forty-four patients were randomized into the 2-step or conventional orthosis groups. Primary outcomes were active DIP joint flexion and extensor lag, pain, and the Abouna-Brown criteria.

RESULTS: The 2-step orthosis was associated with a smaller active DIP extensor lag, compared with the conventional orthosis (-7.5 ± 4.5° vs -16.4 ± 6.9°, P = .001), combined with a significantly higher Abouna-Brown criteria (χ2  = 14.57, P = .01). No other between-group differences were identified.

CONCLUSION: The therapeutic effectiveness of the 2-step orthosis, over a conventional orthosis, was supported by a large effect size of the treatment in improving residual active extensor lag at the DIP and overall Abouna-Brown criteria. Our study thus suggested that the initial immobilization involved in new 2-step orthosis and is thus a good immobilization technique.

LEVEL OF EVIDENCE: Ib.